Wafer heating plate with adjustable lifting ring

Abstract

The present invention discloses a wafer heating plate, comprising a plate body for carrying a wafer and a lifting ring connected to the outer periphery of the plate body in a lifting manner. The lifting ring has a surface that can move between a high position and a low position relative to the reaction surface of the wafer to determine the edge deposition performance of the wafer. The surface of the lifting ring at the low position is lower than the reaction surface of the wafer.

Description

Technical Field

[0001] The invention relates to a wafer heating plate used in semiconductor technology, in particular to a wafer heating plate provided with a lifting ring with adjustable height. Background Art

[0002] Semiconductor plasma processing is used to deposit materials on a substrate to form a thin film, such as using the known plasma chemical vapor deposition (PECVD) method to form a dielectric film on a substrate. Of course, plasma processing can also be applied to atomic layer deposition (ALD) and etching processes. In plasma processing, the plasma distribution, uniformity and density that affect the formation of thin films are critical. This is because these factors will cause differences in the film thickness in the center of the substrate and the film thickness at the edge of the substrate. Appropriate plasma distribution, uniformity and density can obtain a film with uniform thickness. Of course, such an ideal result depends on the adjustment and control of the plasma distribution curve during the process.

[0003] As shown in FIG. 1(A) and FIG. 1(B), an intra-cavity edge adjustment ring 1 is currently used to control the plasma curve in the cavity. The adjustment ring 1 is located on the outer stepped structure 3 or base of the tray 2. The adjustment ring 1 has a height so that the distance between the top or upper surface of the adjustment ring 1 and the wafer carrying surface of the tray 2 is fixed. Even if the support pins 4 lift the wafer W from the process position of FIG. 1(A) to the transfer position of FIG. 1(B), the adjustment ring 1 will not move together. This is sometimes not conducive to the edge deposition performance of a specific process, because different process conditions will result in different edge deposition rates, and a fixed height adjustment ring cannot meet various conditions. See. Figure 2 As shown, the inner side of the edge adjustment ring 1 (ie, facing the wafer) can form an inclined surface or a curved surface, which is used to limit and buffer the impact of the wafer edge, but such a configuration still cannot meet the different edge deposition rates required by different processes.

[0004] Therefore, it is necessary to develop an adjustment ring that can be applied to different process requirements to obtain a better edge deposition effect. Summary of the invention

[0005] The object of the present invention is to provide a wafer heating plate, comprising: a plate body, used to carry the wafer and having an outer periphery larger than the outer diameter of the wafer; and a lifting ring, connected to the outer periphery of the plate body in a liftable manner, so that the vertical distance between an upper surface of the lifting ring and an upper surface of the wafer can be adjusted within a range.

[0006] In a specific embodiment, the periphery has a base, and the lifting ring is connected to the base of the periphery of the disk body in a liftable manner.

[0007] In one embodiment, the bottom of the lifting ring is connected to a servo motor via a support member.

[0008] In one embodiment, the lifting ring has a heating coil.

[0009] Another object of the present invention is to provide a method for using the wafer heating plate, comprising: during one process, lowering the lifting ring so that the upper surface of the lifting ring is lower than the upper surface of the wafer; and during another process, raising the lifting ring so that the upper surface of the lifting ring is higher than the upper surface of the wafer.

[0010] In a specific embodiment, the method of the wafer heating plate includes: while the plurality of support pins of the plate body lift the wafer to a transfer position, the lifting ring is synchronously raised to limit and prevent the lateral deviation of the wafer.

[0011] Another object of the invention is to provide a wafer heating plate, comprising: a plate body for carrying the wafer; and a lifting ring connected to the periphery of the plate body in a liftable manner, so that a surface of the lifting ring can move within a range between a high position and a low position relative to the reaction surface of the wafer to thereby determine the edge deposition performance of the wafer, wherein the surface of the lifting ring at the low position is lower than the reaction surface of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention may be further understood with reference to the following drawings and descriptions. Non-limiting and non-exhaustive examples are described with reference to the following drawings. The components in the drawings are not necessarily to actual size; the emphasis is on illustrating the structure and principle.

[0013] FIG. 1 (A)-(B) show the states of a conventional wafer heating plate at a process position and a transfer position respectively;

[0014] Figure 2 The structure of the known regulating ring;

[0015] 3(A)-(C) are configuration diagrams of the wafer heating plate of the present invention in the first process, the second process and the transmission state;

[0016] Figure 4 It is a partial enlarged view of Figure 3(B). DETAILED DESCRIPTION

[0017] The invention will be described more fully below with reference to the accompanying drawings, and specific exemplary embodiments are shown by way of example. However, the subject matter of the present invention may be embodied in many different forms, and thus the construction of the subject matter covered or claimed is not limited to any exemplary embodiment disclosed in this specification; the exemplary embodiments are merely illustrative. Likewise, the present invention is intended to provide a reasonably broad scope for the claimed subject matter claimed or covered.

[0018] The term "in one embodiment" used in this specification does not necessarily refer to the same embodiment, and the term "in other (some / certain) embodiments" used in this specification does not necessarily refer to different embodiments. It is intended that, for example, the claimed subject matter includes a combination of all or part of the exemplary embodiments.

[0019] Figures 3(A)-(C) are schematic diagrams of the wafer heating plate of the present invention. Figure 3(A) shows the configuration of the wafer heating plate under the first process. Figure 3(B) shows the configuration of the wafer heating plate under the second process. Figure 3(C) shows the wafer at a transfer position.

[0020] The wafer heating plate of the present invention comprises a plate body 31, which can be arranged in a processing chamber (not shown) by known means, and has a carrying surface S for carrying the wafer W. A plurality of supporting pins 32 are driven by a servo motor so that the top ends of the pins can move between above and below the carrying surface S. Although not shown in the figure, the plate body 31 can also be configured with components such as a heating coil, an electrode plate and / or a temperature sensor to meet various process requirements.

[0021] The lifting ring 33 is disposed on the periphery of the disk body 31 and can move vertically relative to the bearing surface S of the disk body 31. The periphery of the disk body 31 has a base 34, which defines the bottom end of the movable range of the lifting ring 33. In this embodiment, the base 34 is a stepped structure, that is, an upward surface of the base 34 is lower than the bearing surface S, and the upward surface defines the lowest position of the lifting ring 33. In other embodiments, the base 34 may have other structural features for cooperating with the bottom of the lifting ring 34.

[0022] The bottom of the lifting ring 33 is connected to a plurality of support rods 35, and the support rods 35 are driven by a servo motor to rise and fall. The lifting mechanism of the lifting ring 33 can be independent of the lifting mechanism of the support pins 32, thereby independently controlling the level of the wafer W and the lifting ring 33.

[0023] 3(A) is located at the lowest position of its movable range, that is, coupled to the upward surface of the base 34. The entire lifting ring 33 is lower than the upper surface of the wafer W, which determines the first deposition rate of the plasma at the edge of the wafer in the first process.

[0024] The lifting ring 33 of FIG. 3(B) is located at a high position, so that the inner side of the lifting ring 33 surrounds the periphery of the wafer W and the top of the lifting ring 33 is higher than the top surface of the wafer W, thereby determining a second deposition rate of plasma at the edge in the second process, and the second deposition rate is different from the first deposition rate.

[0025] The lifting ring 33 and wafer W in FIG3(C) are located at a high position, wherein the wafer W is slightly higher than the lifting ring 33, so that the front end of the robot finger can enter under the wafer W for receiving. In one embodiment, the lifting ring 33 may be provided with a wafer limiting mechanism. When the wafer W is raised from the process position in FIG3(B) to the transfer position in FIG3(C), the lifting ring 33 rises synchronously, so that the wafer W is allowed to be close to the periphery of the wafer W during the process of rising to the top position to prevent the wafer W from shifting. However, the highest positions of the wafer W and the lifting ring 33 are shown in FIG3(C), and the lifting ring 33 is lower than the wafer W to form a space allowing the front end of the robot finger to move.

[0026] Figure 4 FIG3(B) is a partial enlargement of the process position, wherein the lifting ring 33 at the high position has an upward ring surface 331, whose horizontal height is located above the top surface of the wafer W. The height H of the lifting ring 33 can be appropriately selected so that when the lifting ring 33 is at a low position, such as when the bottom of the lifting ring 33 is coupled to the upward surface 341 of the base 34, the upward ring surface 331 can be lower than the top surface of the wafer W or lower than the bearing surface of the plate 31 to determine the edge deposition rate of the process. Of course, the inner side of the lifting ring 33 can be formed with a Figure 2 Those skilled in the art will understand that slight structural changes of the lifting ring 33 will indeed affect the wafer edge deposition effect, so the position of the lifting ring 33 must be appropriately selected according to different structures to obtain the desired edge deposition effect.

[0027] In some embodiments, in addition to adjusting the position of the lifting ring 33 in the vertical range, the lifting ring 33 may also have a mechanism for adjusting the tilt (i.e., the relative tilt relationship between the lifting ring and the plate) to meet more possibilities. For example, the support rods 35 may be controlled by their respective servo motors to increase their lifting degree. In addition, the lifting ring 33 may include a heating coil 332 to maintain the temperature of the edge of the wafer W, so that the edge deposition is better controlled.

[0028] In summary, compared to the conventional fixed surrounding structure of the heating plate, the peripheral structure height of the wafer heating plate of the present invention can be actively adjusted relative to the wafer reaction surface to obtain edge deposition performance that meets the requirements under different processes and keep the film deposition thickness consistent.

Claims

1. A wafer heating plate, comprising: A tray body, used for carrying the wafer and having an outer diameter larger than the outer diameter of the wafer; and A lifting ring is connected to the periphery of the plate in a liftable manner, so that the vertical distance between an upper surface of the lifting ring and an upper surface of the wafer can be adjusted within a range, wherein The upper surface of the lifting ring at a low position is lower than the upper surface of the wafer, and the upper surface of the lifting ring at a high position is higher than the upper surface of the wafer. In addition, while the plurality of support pins of the tray lift the wafer to a transfer position, the lifting ring is raised synchronously so that the lifting ring is close to the periphery of the wafer during the process of the wafer rising to the top position, so as to limit and prevent the lateral displacement of the wafer.

2. The wafer heating plate according to claim 1, characterized in that: The outer periphery of the disk body is provided with a base, and the lifting ring is connected to the outer periphery of the disk body in a lifting manner.

3. The wafer heating plate according to claim 1, characterized in that: The bottom of the lifting ring is connected to a servo motor via a supporting member.

4. The wafer heating plate according to claim 1, characterized in that: The lifting ring has a heating coil.

5. The wafer heating plate according to claim 1, characterized in that: Include: When the wafer and the lifting ring are synchronously lifted to their respective highest positions, the lifting ring is lower than the wafer to form a space allowing the front end of the robot finger to move.

6. A method for using the wafer heating plate according to claim 1, characterized in that: Include: During a process, the lifting ring is lowered so that the upper surface of the lifting ring is lower than the upper surface of the wafer; and During another process, the lifting ring is raised so that the upper surface of the lifting ring is higher than the upper surface of the wafer.

7. A wafer heating plate, characterized in that: Include: A tray for holding wafers; and A lifting ring is connected to the periphery of the disk in a liftable manner, so that a surface of the lifting ring can move between a high position and a low position relative to the reaction surface of the wafer to determine the edge deposition performance of the wafer, wherein the surface of the lifting ring located at the low position is lower than the reaction surface of the wafer, and the surface of the lifting ring located at the high position is higher than the reaction surface of the wafer, and during the period when the multiple support pins of the disk lift the wafer to a transfer position, the lifting ring is synchronously raised, so that the lifting ring is close to the periphery of the wafer during the process of the wafer rising to the top position, so as to limit and prevent the lateral deviation of the wafer.

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